Modern CNC machine controls are more sophisticated and packed with more features than ever before. They are more frequently used to perform a wider variety of jobs. This gives rise to the need for more frequent maintenance work since periodic service intervals or cycle values are reached sooner. Furthermore, there is a lack of consistency of wear between tool parts caused by the wide variety of tool movements possible for any given piece or series of pieces that the tool machines. Since some parts receive more or less wear than others and at varying intervals, difficulties arise in tracking hours of use on a part-by-part basis. Traditional methods of calculating part wear based on gross hours of use for the entire machine are therefore inadequate and inefficient.
Further complicating the task of calculating and tracking wear on machine parts is the difference in measurement units between different types of parts. For certain drive motors, for example, cycle values may be measured in terms of hours, while for other parts such as bearings, tracks and the like, cycle values may be determined by total distance of travel along a track or rail. Electrical contacts may be serviced according to the number of make and break cycles. Maintenance specifications are typically outlined and tracked in a detailed service manual delivered with a CNC machine. An example of such a manual is that of the Thermwood Model 53 CNC machining center from Thermwood Inc., of Dale, Ind., which manual is incorporated herein by reference. Chapter 5 of the Model 53 manual contains detailed service information showing the recommended minimum frequency of lubrication of the listed parts. Further, the Model 53 manual identifies the service points on a detailed diagram of the machine showing the location of points on the machine. Detailed service instructions are also presented.
Although a recommended maintenance schedule can be maintained, tracking the completion of maintenance events, however is left to the user, since, even with recommended lubrication cycle values such as on a daily or weekly basis, parts experiencing more operational travel may need lubrication sooner. Often times however, due to the pressure of making scheduled deliveries and the like, inherent in manufacturing operations, scheduled maintenance events may not be performed or, if performed, may not be properly tracked leading to unnecessary down-times. Further, if maintenance events are not tracked accurately, duplicitous part replacements and maintenance efforts may lead to excessive overall costs of operation of the machine tool.
Scheduled maintenance events must be performed after certain parts have run for a certain number of hours or have accumulated certain distances of travel to avoid premature failure. In such cases, if parts are not serviced after accumulating the predetermined amount of use, failure is imminent. In a typical system, noise, squeaks, vibration, or other telltale symptoms may indicate an impending failure requiring immediate corrective actions. Such warnings, however, may not always be present. Parts may fail spontaneously due to poor lubrication or a lack of adequate maintenance. Such parts may include motors, slides, bearings, electrical contacts and the like. Such parts are in near constant, but variable use, and, therefore, cannot be easily or accurately monitored simply by tracking the hours of aggregate use on the entire machine tool. Using aggregated hours of use on the tool as a measure in determining the maintenance event schedule for individual parts may lead to inefficient maintenance and higher costs, since some parts may have received relatively little use during the aggregate cycle value for the entire tool. If such parts are nevertheless replaced or serviced, unnecessarily higher costs are incurred.
Since the wear on certain parts is dependent on the type of parts being machined, and since a typical CNC machine tool may mill a series of different parts in the course of operation, teach having different demands on the machine's parts, the maintenance event requirements, as described, vary depending on which machine parts accumulate wear first. Tracking the accumulated time on individual components becomes a formidable task.
Further complicating the requirement for servicing inherent in operating a CNC machine tool is the availability of trained personnel to perform the maintenance work. Despite comprehensive manuals detailing the steps in performing certain maintenance event tasks, there is no substitute for live instruction to ensure that steps are performed correctly and that time saving pointers can be given. A manufacturer of CNC machine can provide training and/or trained personnel to a customer but usually only at a premium price. The alternative is for the customers to maintain equipment themselves or to risk equipment breakdowns. By performing unqualified repair or failing to perform scheduled maintenance, manufacturer's warranties may be voided.
Hard copy manuals are inherently easy to misplace or may become damaged or worn. Moreover, indexing through a manual may be time-consuming and may require extensive page turning for each step of what may be a relatively detailed task. Page turning, by technicians with grease, lubricant, or other soil on their hands, may soil manual pages leading to premature degradation of the manual. Attempting repair or maintenance without using the service manual may lead to incomplete or improper maintenance or repair. Even for experienced technicians, the service manual is a crucial reference.
It would be appreciated in the art therefore for a system and method capable of facilitating the performance of key maintenance functions and repairs of failed equipments. Such a system would be integrated into the CNC machine tool and provide the maintenance event support functions and alarm and failure condition monitoring and reporting at a relatively low cost while increasing the operability or "up-time" of the CNC machine tool.